平顶绿光晶化制备多晶硅薄膜

利用倍频Nd∶YAG激光器使玻璃基底上沉积的非晶硅薄膜成功实现了晶化.YAG激光器的倍频绿光经蝇眼透镜阵列整形后得到一光强均匀分布的平顶光束,并用此光束对非晶硅薄膜进行扫描晶化处理.分别测量了激光晶化前后薄膜的拉曼谱和表面形貌.测量结果表明,非晶硅实现了到多晶硅的相变,且晶化处理后表面起伏度明显增大.根据拉曼谱的数据计算了不同激光能量密度下薄膜的粒度大小和结晶度.结果表明,在一定能量密度(400～850 mJcm2)范围内,结晶膜的晶粒粒度和结晶度随激光能量密度升高而增大.然而能量密度大于1000 mJ/cm2后,检测不到明显的多晶硅特征峰.激光能量密度在850 mJ/cm2左右可得到最佳晶化效果.     

基于DSP的无背景模型车流量检测

针对车流量检测中遇到光照变化、树阴、树枝摇动等一系列问题,在运动物体法,背景建模法和时间差分法的基础上,提出了一种基于DSP的无背景模型的新型车流量检测方法。笔者依次使用基于块的帧差法、双重前景融合法、基于纹理对象分割法、假前景滤波法对车流量进行检测。经实验验证,采用无背景模型算法能成功有效地检测车流量,检测准确率达88%,提高了车流量检测的精度。     

Optimal lot-sizing policy for a manufacturer with defective items in a supply chain with up-stream and down-stream trade credits

In this paper, we establish an economic production quantity model for a manufacturer (or wholesaler) with defective items when its supplier offers an up-stream trade credit M while it in turn provides its buyers (or retailers) a down-stream trade credit N. The proposed model is in a general framework that includes numerous previous models as special cases. In contrast to the traditional differential calculus approach, we use a simple-to-understand and easy-to-apply arithmetic–geometric inequality method to find the optimal solution. Furthermore, we provide some theoretical results to characterize the optimal solution. Finally, several numerical examples are presented to illustrate the proposed model and the optimal solution.     

一种双层双联微模块内的空调布置方式的对比分析研究

本文主要研究了一种双层双联微模块产品中列间空调的交错布置方式和相对布置方式,对微模块整体的框架结构系统和空调管路系统的影响,并对两种布局分别进行了CFD温度场和流速场模拟分析。通过研究分析,两种列间空调的布置方式,对这种双层双联微模块的温度场和流速场整体影响不大,两者都能满足设计条件,达到冷却效果。采用列间空调相对布置的方式虽然带来一定的微模块内列间空调的支管管路弯头接口较多,管路稍微复杂的困扰,但是能够减少微模块底座框架结构的种类,增加可通用的底座数量,可减少微模方框架的生产周期,降低生产成本,降低施工难度,提高安装周期。     

基于Excel VBA实现普通高中毕业证书打印系统

介绍如何使用Excel VBA 开发毕业证书打印系统,并给出详细代码.     

Preparation of cobalt ferrite nanoparticles by using spent Li-ion batteries

Cobalt ferrite nanoparticles are a soft magnetic material have been extensively used in many electronic and magnetic applications. In this study, Co_0.8Fe_2.2O₄ nanoparticles with particle size of about 23.5 nm were directly synthesized by sol–gel auto-combustion and calcination methods using spent Li-ion batteries as raw materials. The overall process involves four steps: formation of homogeneous sols; formation of dried gels; combustion of the dried gels; and calcination of the dried gels after combustion at 1173 K for 2 h. The DTA–TG and IR were used to study the auto-combustion and thermal decomposition of the precursor, the morphology and structure of cobalt ferrite nanoparticles were characterized by XRD and TEM techniques. Moreover, the precise metal ion stoichiometry of cobalt ferrite nanoparticles was analyzed by ICP. The results revealed that the auto-combustion process was considered as a heat-induced exothermic oxidation–reduction reaction between nitrate ions and carboxyl group. The XRD patterns of calcination the dried gels after combustion confirmed the single phase spinel structure for the synthesized materials. The crystallite size was calculated from the most intense peak (3 1 1) using the Scherrer equation. The TEM photograph also shown that cobalt ferrite nanoparticles were well-dispersed and with little aggregation.     

Precise Design of Millimeter Wave Quasi-Optical Faraday Rotators

A method of designing high performance millimeter wave quasi-optical Faraday rotators (QOFR) is reported in this paper. First, the dielectric and magnetic parameters for the ferrite sample are determined by fitting theoretical curves to the measured data. These fitted parameters are then used in a precise numerical model to predict the rotation angle and insertion loss of the QOFR. Finally, the parameters of the QOFR are optimized according to the requirements of devices. Examples are given showing the performance of the QOFR with an isolation better than 20 dB and an insertion loss less than 0.6 dB from 75 GHz to 95 GHz.     

基于B/S结构的远程装配实验系统的实现

简要介绍了远程装配实验系统的原理和构成,概述了基于B/S结构的监控软件的结构和涉及的关键技术,展示了该实验系统对于实现远程实验教学和优化利用教学资源的作用.     

超声法检测火药生产中非金属杂质的应用研究

火药生产中非金属杂质带来的安全隐患是一个尚未解决的关键问题;由于超声检测具有适应性强,检测灵敏度高、快捷,无污染,可达到无损检测等特点,选用其作为检测火药生产药料中非金属杂质的方法;对A扫描脉冲反射法应用于检测药料中杂质进行了探索研究,试验结果证实用超声法检测药料中的非金属杂质具有一定可行性.